Today’s 20-year-olds are having less sex than the previous generation. About 15% of adults between the ages of 20 and 24 reported having no sexual partners since they turned 18, according to new research published today in the journal Archives of Sexual Behavior. Just 6% of the previous generation said the same at that age.

“This is part of a general theme of later maturation that’s been pretty well-documented,” said Jean Twenge, lead researcher of the new study and author of the book “Generation Me.”

Just as young adults are now less likely to have jobs and get married and are more likely to live with their parents, part of this sexual trend may have something to do with economic realities, she said. Still, other factors might also explain these results.

“There’s the possibility that technology has something to do with this,” Twenge said. If you’re spending more time texting with your friends and less time in person, she explained, you might have fewer opportunities to “hook up.”Or, more simply, since “there are more ways to entertain yourself,” sex is less important, being just one of many possibilities on a growing list.

What they discovered was that young adults today — millennials (born starting in the 1980s) and iGen (born in the ’90s) — are less likely to be sexually active compared with young adults from Generation X — those born in the 1960s and ’70s. They also discovered that levels of sexual inactivity increased for women more than men, whites more than blacks, those who did not attend college more than those who did, and those who lived in the east more than those in the west.